The cancellous sponge bone block has a high-strength spongy bone shape after the demineralization of a porous, three-dimensional spongy bone structure that supports tissues inside bone for a certain period of time. However, when rehydrated with blood or saline, it gains compressibility and elasticity like a sponge that has absorbed water. When grafted into the irregularly-shaped missing portions of bone, it provides exceptional space preservation and scaffolding properties for bone remodeling. As a 100% allogenic graft material, it is highly biocompatible.